Pyrophosphate ester bleaching agent



ill.

Patented June 7, 1938 deference? PYROPHOSPHATE ESTER BLEACHING AGENT No Drawing. Application July 25, 1934, Serial 20 Claims.

In Germany July 28, 1933 This invention relates to bleaching agents hav-mshould contain at least one alkyl radical of at ing strong Wetting, emulsifying and cleansing properties, and also to processes by which they may be prepared. More particularly it concerns the addition products of pyrophosphate esters of higher molecular alcohol compounds-with oxygen delivering bleaching agents.

Bleaching agents heretofore used or proposed for use in the industrial arts which most clearly approach those of the present invention have been mechanical mixtures of persalts such as the perborates with various soaps, soap powders, alkaline substances and fatty alcohol sulfuric acid esters. All of these mixtures have had the defect that they decompose and lose their available oxygen in a short while when stored, particularly when in a damp atmosphere, with the result that their effectiveness is often considerably impaired before they can be used.

A principal object of the present invention is to provide very effective bleaching agents having strong wetting, emulsifying and mechanically purifying properties which possess almost unlimited stability when stored;

Another object is to provide bleaching and washing agents which because of their neutral character in solution are suitable for many uses both in industry and in the household for treating textiles and other fibrous materials.

Broadly, the process of the present invention comprises reacting higher molecular alcohol compounds with pyrophosphating agents and with peroxide bleaching agents. The higher molecular alcohol compounds suitable include the aliphatic alcohols having at least 8 carbon atoms which may be either saturated or unsaturated, primary or secondary, monohydroxy or polyhydroxy compounds. As examples, there may be mentioned octyl, dodecyl, cetyl, stearyl, carnaubyl, undecyl, and oleyl alcohols. Instead of the alcohols themselves, there also may be used the sulfonation products thereof, particularly their sulfuric acid esters. The saturated monohydroxy primary alcohols having from 8 to 18 carbon atoms are especially suitable.

In addition to, or instead of, the aliphatic alcohols, the hydrocyclic and aromatic alcohols having at least six carbon'atoms may be used such as, for example, cyclohexanol, methyl cyclohexanol, the naphthenyl alcohols and benzyl alcohol. Likewise the sulfonation products of these alcohols may be used. The dialkylethers of polyhydroxy alcohols with mono or other polyhydroxy alcohols, saturated or unsaturated and their sulfuric acid esters are also suitable, which ethers least 3 carbon atoms, the other radical if desired, containing from 1 to 5 carbon atoms. The sulfuric group of the esters of these ethers may be joined either to the short chain or the long chain alkyl radical. Examples of such ethers of which the esters are suitable are the mono-ethyl ether of octadecandiol, and the mono glycol or the glyceryl ether of lauryl alcohol.

The hereinbefore mentioned alcohols and sulfate esters may be referred to collectively by the general formula CnHm(OY)X, wherein 11. is at least 8, m is equal to, more or less than n, a: is at least one and Y is an H atom or an SOsI-I radical.

The pyrophosphating agents suitable in the present process include pyrophosphoric acid itself and its acid and neutral soluble salts. Of the salts, those of the alkali metal are preferred, but there also may be used the alkaline earth salts and the ammonium salt. As examples, sodium pyrophosphate, and potassium pyrophosphate are quite satisfactory. These agents may be collectively referred to by the general formula Z4P2O7, Wherin Z is an H atom, an NH4 radical or a metal capable of producing a water soluble salt with pyrophosphoric acid.

As oxygen delivering bleaching agents there may be mentioned hydrogen peroxide, sodium peroxide, sodium perborate, perboric acid and percarbonate. These compounds are of the general formula Z'O-O-Z", wherein Z and Z are H atoms, alkali metals or radicals of inorganic peroxides or persalts. The hydrogen peroxide may be employed either in the form of an aqueous solution or in the form of vapor, for the addition with the pyrophosphate ester readily takes place.

One feature of the present process is the ability to vary the quantity of available oxygen combined in the phosphate ester of the alcohol whereby products can be produced which are suitable for effecting most any desired degree of bleaching therefore rendering them suitable in many diverse bleaching operations requiring different severity of oxygen treatment.

Example 1.A mixture of alcohols obtainable by the reduction of cocoanut oil fatty acids in a quantity of 400 grams are esterified with 180 grams of pure pyrophosphoric acid at to C. The pyrophosphoric acid is used preferably in a pure form because impurities which are sometimes found in the unpurified product catalyze the final product and prematurely liberate the oxygen in the mass thereby destroying its stability. The esterified reaction product is then search neutralized with 80 grams of caustic soda and thereafter if desired, purified and recrystallized by treatment with alcohol and ether in known manner. A pure sodium pyrophosphoric acid ester is obtained having the formula, RzNazPzov, wherein R represents the alkyl radical of the alcohol, principally the lauryl radical. 664 grams of the pyrophosphoric acid ester salt of the alcohol thus produced are made into a paste by stirring with 215 cc. of hydrogen peroxide of 40% strength. The resulting mass is brought into solution by adding a little alcohol and heat ing if necessary to bring the temperature to about 40 C. As a result of this procedure a chemical addition product is obtained which con tains 2 molecules of hydrogen peroxide for each molecule of the alcohol sodium pyrophosphate. If it is desired to obtain a dried product, this may be accomplished by carefully evaporating the alcohol under a vacuum and absorbing the remainder of the alcohol by an ether treatment. Upon separation of the alcohol an addition product precipitates in the form of a'grainy crystalline salt which can be filtered and thereafter Washed with ether to further purify the same. The product obtained will be found upon saponification and analysis to contain 62% fatty alcohol and 5% active or available oxygen. It will be noticedfurther, that the product is more I readily soluble in water than the pyrophosphoric acid ester of the alcohol itself.

Example 2.200 grams of myristyl alcohol are esterified with 540 grams of pure phosphoric acid at a temperature suitably between about 100 to 110 C. Thereafter the ester is neutralized with 360 grams of caustic soda, thereby forming a product having the formula R.Na9(PsO20). In contrast to the product of Example 1, this substance is insoluble in alcohol. By forming a paste of 464 grams of this purified dry ester with 215 cc. of hydrogen peroxide, a reaction product is obtained which may be purified by adding about 800 cc. of alcohol which addition causes the mass to precipitate out. The alcohol may be satisfactorily removed merely by filtering. By treatment with ether and filtration, a residue is obtained in the form of a grainy crystalline salt. The product possessesa content of 28% fatty alcohol and 8% active oxygen. It is very readily soluble in water and has a .very outstanding foaming capacity.

- The formula of this and the other novel products described herein have not been definitely determined. Laboratory study indicates, however, that the reaction of the peroxide bleaching agent employed enters a second oxygen atom between one or more of the phosphorous atoms of the pyrophosphoric acid ester thereby forming the arrangement, PO-O-P. The ester produced by the method of this example appears to have six phosphorous atoms joined through five oxygen atoms and has been found to take up a maximum of five additional oxygens when reacted with hydrogen peroxide, which latter oxygen atoms remain active and. available for bleaching action. It should be understood, however, that the present invention is not to be limited to any theory of reaction.

' Example 3.--Twenty kgs. o'f'a mixture of alcohols such as described in Example 1 are sulfonated with kgs. of concentrated sulfuric acid at a temperature suitably at about 60 C. or lower if desired. During stirring 40 kgs. of anhydrous sodium pyrophosphate are-slowly added into the acid sulfonation product. The mass should be cooled if such is necessary to maintain the temperature below 100 C. After about two hours the sodium pyrophosphate powder is completely dissolved and reacted and a viscous redbrown substance obtained which when mixed with water forms a clear solution. The treatment with the pyrophosphate re-esterifies the alcohol by substituting pyrophosphate groups for most of the sulfate groups. In order to add bleaching properties the reaction product is introduced into 5'7 kgs. of hydrogen peroxide of 40% strength. After itgoes completely into solution the mass may be further treated by adding "14 kgs. of anhydrous sodium pyrophosphate. During a substantial increase in temperature a homogeneous smooth paste is obtained having a content of 11% fatty alcohol and 11% hydrogen peroxide. This paste is readily soluble in Water and is exceedingly stable during storage. It can be easily dried and ground into a fine powder, which powder on analysis is found to possess 14% fatty alcohol and 16% active oxygen.

Example 4.Two hundred kgs. of a mixture of alcohols such as specified in Example 1 are sul fonated with 108 kgs. of chlorosulfonic acid at about 50 C. When the temperature has risen to 70-80 C. the acid sulfonation product is added during stirring into a mass composed 'of 330 kgs. of sodium pyrophosphate dissolved in 900 liters of Water. A reaction takes place and a neutral, viscous solution results which may be advantageously dried by atomization in a drying plant at a temperature of about 105 C. The powdered product obtained in this manner contains about fatty alcohol and 50% pyrophosphoric acid. The bleaching properties may be added by treating this product with one or more inorganic persalts in any desired proportions, thereby forming an exceedingly stable powdered bleaching agent.

Eztample 5.Two hundred kgs. of a mixture of alcohols such as described in Example 1 are sulfonat'ed with 108 kgs. of chlorosulfonic acid at about 50 C. as described in Example 4. At a temperature of about 7080 C. the reaction product is introduced into a solution of 333 kgs. of pyrophosphate dissolved in 900 liters of a 20% hydrogen peroxide solution. Upon cooling a White compact, readily soluble paste is obtained which hydrolizes neutrally in water and possesses a content of 13% fatty alcohol and 10 hydrogen peroxide. The product is very stable and does not show a perceptible decrease in active oxygen content, nor a tendency to decompose in any other respect over periods of several months. 'Hereinbelow a table is set out to show the superiority of the products of the present invention over compositions heretofore used or proposed in the industrial arts:

From this table it will be observed that the iiLt/liiiitiii & LYtilfiii; till? ltiiifilll i CAUQN ill or lEXlilES t asses,

addition products, as shown in Examples 1 and 2, of peroxide bleaching agents with pyrophosphate esters. of higher molecular alcohols, constituting the agents of the present invention, possess a much greater stability than the mechanical mixtures, as shown in Example 3 of persalts, with wetting agents, of which the sulfuric acid ester of fatty alcohols are examples.

' The common bleaching soap powders, frequently heretofore employed, which besides persalts also contain sodium silicate are quite strongly alkaline, and as a consequence their field of usefulness is considerably limited. In contrast thereto the addition products of peroxide compounds with higher molecular alcohol compounds, as described herein, form neutral or only slightly alkaline solutions and therefore can be very successfully used in many fields including natural and artificial fiber treatments. The products do not injure fibers and do not injure fast dyes. Because of the high surface activity of the new products, the active oxygen liberated from the reagents during use is eifective to a much higher degree than in prior products, for the reason that the bleaching agent penetrates more readily into the center of the fibers where color impurities are found which for best results must be removed.

The novel bleaching agents are of particular value in the treatment of textiles in the industrial arts as well as in the household wherever a combined bleaching and Washing is desired. They are excellently suitable for use with vat dyeing operations wherein oxidizing and soap treatments are necessary. These two treatments instead of being effected in succession may now be successfully carried out at one and the same time. Dyeings and printings wherein dyes of the indanthrene type are employed are particularly advantageously effected.

Many other industrial operations are improved by the use of these products, for example, they may be used successfully in the degumming of raw silk, for the preboiling of cotton at the so called half bleach stage and for bleaching cotton which has been partially bleached with chlorine.

In general it may be said that the invention in its broadest aspects includes as an initial material any alcohol capable of forming esters with pyrophosphoric acid compounds by either direct or indirect action, possessing emulsifying and cleansing properties of a degree commensurate with the requirements of the use for which the final product is intended.

The initial reaction of the alcohol compound with the sulfonating agent, as described in several of the examples, may be substituted by a reaction with any other acid capable of facilitating the esterification with the pyrophosphoric acid. For example, an acetylation or a boration of the alcohol can be employed with beneficial results though at a greater expense.

It should be understood that the present invention is not limited to the specific substances or the proportions of materials herein given, but that it includes all similar substances and all other proportions coming within the tenor of the whole specification.

I claim:

1. The process of producing bleaching and washing agents comprising reacting a higher molecular alcohol compound having at least 6 carbon atoms with a pyrophosphating agent and with a peroxide bleaching agent.

Eras iitleiellte 2. The process of producing bleaching and washing agents comprising reacting a higher molecular aliphatic alcohol having at least 8 carbon atoms with a pyrophosphating agent and with a peroxide bleaching agent.

3. The process of producing bleaching and washing agents comprising reacting a sulfonated higher molecular alcohol compound having at least 6 carbon atoms with a pyrophosphating agent and with a peroxide bleaching agent.

4. The process of producing bleaching and Washing agents comprising reacting a sulfuric acid ester of a higher molecular aliphatic alcohol having at least 8 carbon atoms with a pyrophosphating agent and with a peroxide bleaching agent.

5. In the production of bleaching and washing agents the step comprising reacting a water soluble salt of pyrophosphoric acid ester of a higher molecular alcohol compound having at least 6 carbon atoms with a peroxide bleaching agent.

6. In the manufacture of bleaching agents having wetting, emulsifying, and cleansing properties, the step comprising reacting an alkali metal salt of pyrophosphoric acid ester of a higher molecular aliphatic alcohol having at least 8 carbon atoms with a peroxide bleaching agent.

7. The process comprising reacting a sulfonate-d mixture of alcohols obtained by reduction of fatty acids of cocoanut oil with an alkali metal salt of pyrophosphoricacid, and combining said product with a hu'antity of 'sodium perborate dependent upon the content of available oxygen desired in the final product.

8. The process of manufacturing bleaching agents having wetting, emulsifying and cleansing properties, comprising neutralizing a pyrophosphoric acid ester of a higher aliphatic alcohol having at least 8 carbon atoms and reacting the resulting salt with hydrogen peroxide.

9. The process of producing washing and bleaching agents comprising sulfating a higher molecular alcohol having at least 8 carbon atoms, re-esterifying the alcohol sulfate with a pyrophosphating agent whereby most of the sulphuric groups are replaced, and reacting the mass with a peroxide bleaching agent.

10. The process of producing washing and bleaching agents comprising sulfating a higher molecular alcohol having at least 8 carbon atoms, re-esterifying the alcohol sulfate with a pyrophosphating agent whereby most of the sulfuric groups are replaced, reacting the mass with hydrogen peroxide and adding sodium pyrophosphate to form a paste.

11. The process of producing washing and cleaning agents having bleaching properties comprising sulfonating an alcohol having at least 6 carbon atoms, reacting the resulting product with anhydrous sodium pyrophosphate and then with hydrogen peroxide.

12. A hydrogen peroxide derivative of a soluble salt of a pyrophoshate ester of an alcohol having at least 6 carbon atoms.

13. A soluble salt of pyrophosphoric acid ester of an aliphatic alcohol having at least 8 carbon atoms containing a combined oxygen-delivering bleaching agent.

14. A pyrophosphate ester of a sulfonated aliphatic alcohol having at least 8 carbon atoms combined with a peroxide bleaching agent.

15. A sodium salt of a pyrophosphate ester of lauryl alcohol having combined therewith an oxygen delivering bleaching agent of the type search them Z-O-OZ wherein Z and Z" represent members of the group consisting of H atoms, alkali metals or radicals of inorganic peracids or persalts. v

16. The process comprising reacting a compound of the general formula CnHm(OY) x, Wherein n is at least 8, m is equal to, more or less than n, a: is at least 1, and Y is an H atom or an SOsH radical with a pyrophosphating agent of the general formula Z4P2O7, wherein Z represents a member of the group consisting of an H atom; NI-Ir or a metal producing'a water soluble salt and with a compound capable of delivering active oxygen of the general formula Z'-O-O-Z", wherein Z and Z represent members of the group consisting of H' atoms, alkali metals or radicals of inorganic peracids or persalts.

17. The process comprising reacting a compound of the general formula R(OY):v, wherein R is a radical of an aliphatic alcohol having at least 8 carbon atoms, a: is at least 1, and Y represents a member of the group consisting of an H atom or an SO3I-I radical with a pyrophosphating agent of the general formula Z4P2O'1, wherein Z represents a member of the group consisting of an H'atom, NH4 or a metal producing a water soluble salt and with a compound capable of delivering active oxygen of the general formula ZOOZ", wherein Z and Z" represent members of the group consisting of H atoms, alkali metals or radicals of inorganic peracids or persalts.

18. The process of producing washing and bleaching agents comprising sulfating a mixture of alcohols obtained by reduction of fatty acids KARL BUTZ. 

